用线性插值法求单摆运动周期的近似解

利用线性插值的方法,提出了一个任意摆角条件下的单摆运动周期的近似公式.并利用Mathematica软件将该公式与精确解进行了比较,还与其他近似公式进行了对比.结果表明,该公式的近似程度相当好.     

The entropies of renewal systems

Renewal systems are symbolic dynamical systems originally introduced by Adler. IfW is a finite set of words over a finite alphabetA, then the renewal system generated byW is the subshiftX _W ⊂A ^Z formed by bi-infinite concatenations of words fromW. Motivated by Adler’s question of whether every irreducible shift of finite type is conjugate to a renewal system, we prove that for every shift of finite type there is a renewal system having the same entropy. We also show that every shift of finite type can be approximated from above by renewal systems, and that by placing finite-type constraints on possible concatenations, we obtain all sofic systems. The authors were supported in part by NFS grants DMS-8706284, DMS-8814159 and DMS-8820716.     

Solution Transformations and Their Effects on the Systems with Open Boundary Conditions

The solution transformations and properties of the R-matrices for two-component systems under these transformations are analyzed in details.Not all transformed R-matrices can be put into the Skalyanin‘s formalism.For those R-matrices with all required properties,the effects of solution transformations to the six-and eight-vertex systems with open boundary conditions are discussed.these effects can be one of the following types:the Hamiltonian is invariant or transposition-invariant or made in a similarity transformation,or its coupling coefficients are multiplied by an overall factor,or the spin of the system is rotated around the z axis or/and reflected with respect to some plane.In these cases,the transformed systems remain to be integrable.     

Preparation of Polyclonal Antibodies Against Testis-specific Protease 50 and Characterization of Antibody Specificity

Introduction TheTSP50genehasbeenidentifiedasoneofthe testis specificoncogenes,whichisexpressedathigh levelsinapproximately92%ofhumanbreastcancer samples,makingitanattractivemolecularmarkerand apotentialtargetfordiagnosisandtherapy[1].Itisho mologoustomany…     

Atomic layer deposition in nanometer-level replication of cellulosic substances and preparation of photocatalytic TiO2/cellulose composites

TiO2 replicas of filter paper with nanometer-level accuracy were prepared by atomic layer deposition of thin conformal TiO2 coating, followed by a removal of the paper by air-anneal at 450 degrees C. Photocatalytic anatase TiO2/cellulose composites were also made by leaving the paper intact. The TiO2 films were deposited from Ti(OMe)4 and H2O at 150-250 degrees C. The photocatalytic activity of the TiO2/cellulose composite was verified by photocatalytic reduction of Ag(I) from an aqueous solution to Ag nanoparticles on the TiO2 surface. The TiO2/cellulose composites are mechanically more stable than the free-standing TiO2 replicas and are therefore potentially suitable as lightweight, high surface area photocatalysts.     

Application of symplectic algorithms to QCT calculation:H+H_2 system

The basic theory of symplectic algorithm was introduced. A comparison between Runge-Kutta method and symplectic integration method was preformed in the simulation of the long time behavior of H + H2 system on BKMP potential energy surface. Our results reveal a dis-sipative behavior in the integral of ordinary differential equation by the fourth order Runge-Kutta method, which causes incorrect simulation results in QCT calculations. However, when the symplectic integration method is applied, the dissipative behavior is not found in the same system. When the initial state is the same, the energy deviation of fourth order symplectic integral method is almost one percent of that of fourth order Runge-Kutta method in a 60000-step simulation, and that of sixth order symplectic integral method is much less. These results show that the symplectic integral methods are always the better choice in the integral calculation of the long time behavior in maintaining energy conservation.     

变分过渡态理论对OCS,CO2,CS2体系的研究

本文用变分过渡态理论,首次对无鞍点的释能反应O+CS→CO+S、O+CO→CO+O和S+CS→CS+S进行了动力学研究,考察了反应动力学瓶颈区性质,计算了反应的速度常数,并将O+CS反应的速度常数值与实验值及经典轨迹计算结果进行了比较,三者基本相符.     

偶氮胂-DBS用于光度法测定牛血清白蛋白

在室温下,于pH 2.5的Britton-Robinson缓冲溶液中及非离子表面活性剂OP存在下,牛血清白蛋白(BSA)与偶氮胂-DBS的复合物的最大吸收在514 nm波长处,但显色复合物与试剂空白吸光度之差在370 nm处最大,选择在370 nm处测定,反应迅速完成。非离子表面活性剂OP可提高反应灵敏度及复合物稳定性。乙醇可提高体系灵敏度。BSA的质量范围在0~60.0 mg.L-1范围内符合比耳定律,方法表观摩尔吸光率3ε70 nm=8.58×105L.mol-1.cm-1。方法用于测定血清样品中蛋白质的总量,5次测定值的RSD为0.60%,回收率为98.0%。     

载铜5A分子筛在汽油模拟体系中脱硫性能的研究

近年,美国环保局计划将汽油中硫的质量分数从当前的300×10-6降到2006年的30×10-6,欧盟也已经通过了新的汽油硫质量分数标准为30×10-6~50×10-6,德国甚至提出计划使用无硫汽油[1]。中国汽油硫的质量分数高达800×10-6以上,与世界汽油品质距离甚远。因此汽油中硫化物的脱除成为当务之急。目前,脱硫技术主要有催化裂化脱硫、催化加氢脱硫、水蒸气脱硫、生物催化脱硫、吸附精制脱硫、氧化脱硫等[2~5]。吸附精制法具有净化度高、能耗低、易于操作等优点,高效的脱硫吸附剂制备是过程开发的关键。负载金属离子的活性纤维是脱除汽油中硫醇的一种…     

Seeding and the Non-Hydrolytic Sol-Gel Synthesis of ZrW2O8 and ZrMo2O8

The unseeded non-hydrolytic sol-gel synthesis of ZrW₂O₈ and ZrMo₂O₈ produces trigonal ZrM₂O₈ (M = W, Mo) at 740 and 300–400°C, respectively. Cubic ZrW₂O₈ can be prepared using non-hydrolytic sol-gel methods by seeding with small amounts of preprepared cubic material, and the formation of the trigonal polymorph can be suppressed completely. Seeds with a small particle size are necessary for the preparation of cubic ZrW₂O₈. In contrast, seeding of ZrMo₂O₈ gels with either cubic ZrMo₂O₈ or cubic ZrW₂O₈ only lowers the temperature at which the trigonal phase crystallizes.